A variety of different types of rotary internal combustion engines are known in the patented prior art including rotary piston engines in which the piston rotor assembly is equipped with vanes or abutments against which the forces generated by fuel explosion react to produce rotation of the rotor assembly. Such engines, while varying in their specific configurations, all have a common drawback of excessive friction and rapid wear which greatly diminishes useful life of the engine and cuts its operational efficiency.
One prior art rotary engine which at least partly overcomes the above-stated drawback of engines having rotary abutments is disclosed in U.S. Pat. No. 4,182,301, issued to Joe O. Dean. This particular engine employs a system of low friction vane-piston rollers in intermeshing relationship on two counter-rotating rotors which are disposed eccentrically in two communicating chambers of a fixed housing. This patented engine closely simulates the operational cycles of a four stroke cycle piston engine with greatly reduced friction compared to most prior art rotary engines but is still lacking somewhat in simplicity of construction, minimized weight and low cost of manufacturing to satisfy completely the needs of the art.
The present invention seeks to completely satisfy the needs of the art for a low cost, highly simplified, minimal weight rotary piston engine which has a true four stroke operational cycle, reduced friction and improved operational efficiency in terms of usable power produced for a given total cylinder displacement in the engine.
A unique feature of the rotary piston engine in accordance with the present invention resides in the provision of a central satisfactory but rotationally adjustable cam which is profiled to dictate the four stages or phases of operation which collectively make up the four stroke cycle of a piston engine, namely, intake, compression, power and exhaust. The profiled surface of the stationary cam is followed by rollers on the connecting rods of the pistons which reciprocate in the several cylinder chambers of the engine rotor. The connecting rods carrying the cam follower rollers are not attached to the stationary profiled cam and are free to orbit around the cam with the rotor body pistons to thereby generate the necessary piston movements in a four cycle engine.
Other features and advantages of the invention over the prior art will become apparent during the course of the following detailed description.